Laser optical fiber tray

ABSTRACT

A laser optical fiber tray is generally presented. In some embodiments, the optical fiber tray comprises an enclosure, coupled with a laser system rack, having an opening in the enclosure to accept a feeding fiber exiting from the laser system rack, an opening in the enclosure to allow passage of the feeding fiber out of the enclosure, and a user-accessible space within the enclosure to contain a length of the feeding fiber. In some embodiments, the optical fiber tray is mounted to a top panel of the laser system rack. In some embodiments, the optical fiber tray is mounted to a top panel of an external module which is mounted to a top panel of the laser system rack. Other embodiments are also disclosed and claimed.

CLAIM OF PRIORITY

The present application claims priority to U.S. Non-Provisionalapplication Ser. No. 15/687,072 filed on Aug. 25, 2017 and entitled“LASER OPTICAL FIBER TRAY”, now U.S. Pat. No. 9,971,116, which claimspriority to U.S. Provisional Application No. 62/380,260 filed on Aug.26, 2016, and entitled “LASER OPTICAL FIBER TRAY” both of which areincorporated by reference in their entireties.

BACKGROUND

Lasers are commonly used in materials processing, including cutting,welding, brazing, surface treatment and other applications. Lasersystems are offered in many different configurations, or are customdesigned, to meet the needs of customers, not only in terms ofproperties/intensities of light, but also in terms of feeding fiberdesign and length. Damage to a feeding fiber can be quite costly fromboth a cost of replacement and a cost of system downtime point of view,as the feeding fiber is generally not easily replaceable. Therefore,there is a need for a laser optical fiber tray that can protect thefeeding fiber when not in use and can be adjustable to the length ofexposed feeding fiber needed at a given time.

BRIEF DESCRIPTION OF THE DRAWINGS

The material described herein is illustrated by way of example and notby way of limitation in the accompanying figures. For simplicity andclarity of illustration, elements illustrated in the figures are notnecessarily drawn to scale. For example, the dimensions of some elementsmay be exaggerated relative to other elements for clarity. Further,where considered appropriate, reference labels have been repeated amongthe figures to indicate corresponding or analogous elements. In thefigures:

FIG. 1 is a block diagram of an example laser system, in accordance withsome embodiments;

FIG. 2 is a 3D drawing of an example laser system, in accordance withsome embodiments;

FIG. 3 is a 3D drawing of an example laser system including an opticalfiber tray, in accordance with some embodiments;

FIG. 4 is an overhead drawing showing the interior of an example opticalfiber tray, in accordance with some embodiments;

FIG. 5 is a drawing of a bottom of an example optical fiber tray, inaccordance with some embodiments;

FIG. 6 is a drawing of a top of an example laser rack, in accordancewith some embodiments;

FIG. 7 is a diagram of an example laser system with an optical fibertray, in accordance with some embodiments;

FIG. 8 is a diagram of an example laser system with an external module,in accordance with some embodiments;

FIG. 9 is a flowchart of an example method of assembling a laser system,in accordance with some embodiments; and

FIG. 10 is a flowchart of an example method of readying a laser systemfor use, in accordance with some embodiments.

DETAILED DESCRIPTION

One or more embodiments are described with reference to the enclosedfigures. While specific configurations and arrangements are depicted anddiscussed in detail, it should be understood that this is done forillustrative purposes only. Persons skilled in the relevant art willrecognize that other configurations and arrangements are possiblewithout departing from the spirit and scope of the description. It willbe apparent to those skilled in the relevant art that techniques and/orarrangements described herein may be employed in a variety of othersystems and applications other than what is described in detail herein.

Reference is made in the following detailed description to theaccompanying drawings, which form a part hereof and illustrate exemplaryembodiments. Further, it is to be understood that other embodiments maybe utilized and structural and/or logical changes may be made withoutdeparting from the scope of claimed subject matter. It should also benoted that directions and references, for example, up, down, top,bottom, and so on, may be used merely to facilitate the description offeatures in the drawings. Therefore, the following detailed descriptionis not to be taken in a limiting sense and the scope of claimed subjectmatter is defined solely by the appended claims and their equivalents.

In the following description, numerous details are set forth. However,it will be apparent to one skilled in the art, that the presentinvention may be practiced without these specific details. In someinstances, well-known methods and devices are shown in block diagramform, rather than in detail, to avoid obscuring the present invention.Reference throughout this specification to “an embodiment” or “oneembodiment” means that a particular feature, structure, function, orcharacteristic described in connection with the embodiment is includedin at least one embodiment of the invention. Thus, the appearances ofthe phrase “in an embodiment” or “in one embodiment” in various placesthroughout this specification are not necessarily referring to the sameembodiment of the invention. Furthermore, the particular features,structures, functions, or characteristics may be combined in anysuitable manner in one or more embodiments. For example, a firstembodiment may be combined with a second embodiment anywhere theparticular features, structures, functions, or characteristicsassociated with the two embodiments are not mutually exclusive.

As used in the description of the invention and the appended claims, thesingular forms “a”, “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. It willalso be understood that the term “and/or” as used herein refers to andencompasses any and all possible combinations of one or more of theassociated listed items.

The terms “coupled” and “connected,” along with their derivatives, maybe used herein to describe functional or structural relationshipsbetween components. It should be understood that these terms are notintended as synonyms for each other. Rather, in particular embodiments,“connected” may be used to indicate that two or more elements are indirect physical, optical, or electrical contact with each other.“Coupled” may be used to indicated that two or more elements are ineither direct or indirect (with other intervening elements between them)physical or electrical contact with each other, and/or that the two ormore elements co-operate or interact with each other (e.g., as in acause an effect relationship).

The terms “over,” “under,” “between,” and “on” as used herein refer to arelative position of one component or material with respect to othercomponents or materials where such physical relationships arenoteworthy.

As used throughout this description, and in the claims, a list of itemsjoined by the term “at least one of” or “one or more of” can mean anycombination of the listed terms. For example, the phrase “at least oneof A, B or C” can mean A; B; C; A and B; A and C; B and C; or A, B andC.

A laser system generally includes a rack with a plurality of lasermodules mounted in the rack to drive light through an optical fiberexiting the system. The exiting fiber, or feeding fiber, can extenddozens of feet in length for inclusion in large material processingtools, for example. Conventionally, the feeding fiber is exposed, andsubject to environmental hazards, when not in use. Shipping andrelocating of a laser system can be particularly high risk events forthe feeding fiber. In some embodiments described hereinafter, theoptical fiber tray may include an enclosure to safely coil and store thefeeding fiber. In some embodiments described hereinafter, the opticalfiber tray may include coil guides that define a minimum diameter for aloop of the feeding fiber to be contained within the enclosure. Also, insome embodiments, one or more external modules may be included betweenthe rack and the optical fiber tray, as described in more detailhereinafter, to further customize properties of the laser beam and/or toprovide a connection point where the feeding fiber can be swapped out ifnecessary.

Some benefits of the laser optical fiber tray and external moduledescribed hereinafter include, but are not limited to, enhancedreusability, durability, serviceability, and expandability. For example,the same laser system rack with rack-mounted laser modules can becomemore standardized with customizations added (after initial delivery anduse in some cases) to an external module or optical fiber tray to createa specific laser system to meet the customer needs potentially in termsof modulation frequency, rise/fall times, beam quality, wavelength,fiber properties and fiber length. This can lead to reduced design timeby allowing the same laser system rack to be reused among variousproduct lines without have to increase rack height to accommodateadditional modules. Additionally, not only would the feeding fiber bebetter protected from damage with the use of the optical fiber tray, theuse of a coupler in the optical fiber tray or external module can enablethe quick replacement of the feeding fiber in the event of damage to theoriginal feeding fiber or in the event of system modification requiringa change to a different feeding fiber.

A block diagram of an example laser system that may benefit fromincorporating embodiments of the present invention is depicted inFIG. 1. As shown, laser system 100 includes power distribution module102, pump modules 104, combiner/gain module 106, exit fiber 108, ACinput 110, AC output 112, optical fibers 114, and circuit branches 116.Different and/or additional modules may be included in laser system 100without deviated from the scope of the present invention. For example,separate or multiple combiner/gain modules may be used. Also, any numberof pump modules 104 may be present. In one embodiment, six pump modulesare included in laser system 100. Laser system 100 may be a direct diodelaser system, a fiber laser system, or any other type of laser systemthat may benefit from incorporating embodiments of the presentinvention.

Power distribution module 102 may distribute power in the form of ACVoltage received as AC input 110 to pump modules 104 and combiner/gainmodule 106 through AC output 112. Circuit branches 116 within powerdistribution module 102 may include circuit components to branch ACinput 110 into multiple independent AC outputs 112. In some embodiments,AC input 110 is 3 phase AC which is distributed through circuit branches116 as single phase AC outputs 112. In some embodiments, circuitbranches 116 may also convert AC Voltage to DC Voltage for use withadditional components (not shown) in laser system 100.

Circuit branches 116 may include a circuit breaker, a contactor, a linefilter, and/or a terminal block for each AC output 112. The componentsof circuit branches 116 may be chosen based on the voltage and currentrequirements of modules 104 and 106. In one embodiment, each of ACoutputs 112 provide 480 VAC, though the present invention is not solimited. In some embodiments, AC output 112 may vary by module. Forexample, AC output 112 may deliver a different voltage or a same voltageat a different amperage to pump module 104 than AC output 112 deliversto combiner/gain module 106.

Circuit branches 116 may be designed to protect modules coupled with ACoutputs 112 from damage caused by overcurrent or overload or shortcircuit. Circuit branches 116 may interrupt current flow through one ormore of AC outputs 112 after protective relays detect a fault. Circuitbranches 116 may be manually or automatically resettable after a fault.Additionally, circuit branches 116 may attenuate conductedelectromagnetic interference (EMI) from AC input 110 to AC outputs 112.Circuit branches 116 may be controlled by software or firmware eitherinternal to or external from laser system 100.

One or more pump modules 104 may be included in laser system 100 todrive light through optical fibers 114. In some embodiments, each ofpump module 104 may include a DC power supply to convert AC output 112into direct current that powers laser diodes. In some embodiments, eachof pump module 104 includes one or more liquid-cooled coldplate(s) forheat dissipation.

Combiner/gain module 106 may include coiled fiber to increase lightoutput and may combine optical fibers 114 into a single exit fiber 108that exits laser system 100. Additional modules (not shown) may beincluded in laser system 100 to control and/or condition the lightdriven through exit fiber 108 when laser system 100 is operating.

Exit fiber 108 may have any diameter and length. In one embodiment, exitfiber 108 is up to 75 feet in length. Exit fiber 108 may be a singlelength of fiber or may be multiple lengths of fiber coupled together. Insome embodiments, a first shorter exit fiber 108 is coupled with acoupler or other optical product which is coupled with a second longerfiber. Additionally, in some embodiments exit fiber 108 may be singleclad while in some embodiments exit fiber 108 may be double clad.

Turning now to FIG. 2, a 3D drawing of an example laser system, inaccordance with some embodiments, is shown. Laser system 100 may includerack 200, power distribution module 102, exit fiber 108, laser modules202, and rack top panel 204. Rack 200 may provide the structure andmounting points for supporting and containing the various modules oflaser system 100. Rack 200 may be of standard or non-standarddimensions. Rack 200 may include additional elements not shown or may beimplemented without all elements shown (for example wheels). Rack toppanel 204 may include openings and features, as described in more detailhereinafter, to enable aspects of a laser optical fiber tray.

In some embodiments, rack 200 includes a 23-inch standardized rack framefor mounting laser modules 202. In some embodiments, rack 200 includes a19-in standardized rack frame. In other embodiments, different rackwidths may be used. In some embodiments the height of rack 200 isstandardized in multiples of 1.752 inches or one rack unit or U. In oneembodiment, rack 200 is 28 U tall. In other embodiments different rackheights may be used. In some embodiments, rack 200 is a four verticalpost rack that allows for mounting rails to support laser modules 202 atthe front and rear. In other embodiments, rack 200 is a two verticalpost rack. In some embodiments, rack 200 is open in construction, whilein other embodiments rack 200 is enclosed, for example by doors, sidepanels and a top.

Rack 200 may have provisions for airflow and cooling of laser modules202. In some embodiments, front and/or side air intakes are included aswell as rear exhaust. Forced air fan cooling may or may not be included.In some embodiments, liquid cooling is provided to each of laser modules202 in the form of cold plates supported by conduit, pumps, liquidinlets, liquid outlets, and drains.

Power distribution module 102 and laser modules 202 (which may includepump module 104 and combiner/gain module 106) are mounted within rack200. Power distribution module 102 may have both AC and DC outputs.

Exit fiber 108 may exit laser system 100 through an opening in rack toppanel 204. Exit fiber 108 may include many feet of optical fiber tointerface with external tools (not shown). Conventionally, laser system100 may be shipped or stored with exit fiber 108 laying on rack toppanel 204 exposed to the environment without protection or containment.In some cases, a cardboard box may be used conventionally to provide ameasure of packaging.

FIG. 3 is a 3D drawing of an example laser system including an opticalfiber tray, in accordance with some embodiments. As shown, laser system100 may include rack 200, optical fiber tray 300, depth 302 and width304. Optical fiber tray 300 may be seated on, and interface with racktop panel 204. Some of the ways in which optical fiber tray 300 and rack200 may interface are described in more detail herein, for example withreference to FIGS. 5, 6, 7 and 8.

In some embodiments, optical fiber tray 300 is made of steel or othermetals. In some embodiments, the enclosure of optical fiber tray 300 ismade of the same material and thickness as rack 200. One skilled in theart would appreciate that based at least on the materials used, opticalfiber tray 300 can provide a relatively strong and durable enclosure toprotect the feeding fiber from many common environmental hazardsassociated with shipping and storage.

As shown, optical fiber tray 300 and rack 200 may be substantially equalin both depth 302 and width 304. One skilled in the art would appreciatethat by being substantially equal in two dimensions, not only maymanufacturers be able to offer an aesthetically pleasing laser system100, but they would also be able to maximize the volume within opticalfiber tray 300 to hold feeding fiber, and potentially other components,while limiting the height of optical fiber tray 300. However, in someembodiments, optical fiber tray 300 may only be substantially equal withrack 200 in one of depth 302 or width 304, but not both dimensions. Inother embodiments, optical fiber tray 300 is not substantially equalwith rack 200 in either depth 302 or width 304.

FIG. 4 is an overhead drawing showing the interior of an example opticalfiber tray, in accordance with some embodiments. As shown, the interiorof optical fiber tray 300 may include feeding fiber 402, side fiberopening 404, split bushing 406, inner coil guides 408, outer coil guides410, minimum coil diameter 412, ties 414, liquid supply port 416, liquidreturn port 418, liquid supply conduit 420, and liquid return conduit422. Optical fiber tray 300 would include a top panel in mostembodiments that would need to be removed to access the interior ofoptical fiber tray 300, however it is not shown in this figure.

Side fiber opening 404 in optical fiber tray 300 may allow passage offeeding fiber 402 out of the enclosure. In some embodiments the size ofside fiber opening 404 allows for passage of feeding fiber 402 as wellas attachments to an end of feeding fiber 402. In some embodiments, whenlaser system 100 is not in use, the entire length of feeding fiber 402can be contained within optical fiber tray 300. In other embodiments,when laser system 100 is not in use, a portion of feeding fiber 402 orattachments thereon may remain within side fiber opening 404. In someembodiments, to adjust the length of feeding fiber 402 that extends outof optical fiber tray 300, split bushing 406 must first be removed fromside fiber opening 404. Feeding fiber 402 may then be able to beuncoiled and passed through side fiber opening 404 to the extent needed,for example for using laser system 100 with a material processing tool.When the desired length of feeding fiber 402 is outside of optical fibertray 300, split bushing 406 may then be disposed within side fiberopening 404 to grip feeding fiber 402 and resist further passage offeeding fiber 402 in or out of side fiber opening 404.

In some embodiments, split bushing 406, which may be made of plastic orrubber and may have smooth surfaces to contact feeding fiber 402, mayalso protect feeding fiber 402 from contacting any edges of opticalfiber tray 300 at side fiber opening 404. One skilled in the art wouldappreciate that by exposing only as much of the length of feeding fiber402 as is needed for use at a given time to potential environmentalhazards outside of optical fiber tray 300, there is less risk to anyexcess of feeding fiber 402 that isn't being used. Additionally, thelength of feeding fiber 402 being used at a given time may be able to bemore easily managed and kept under control without bends or loops.

Inner guide posts 408 and outer guide posts 410 may be affixed to thebottom of optical fiber tray 300. Inner guide posts 408 may be spacedapart by a distance that defines minimum coil diameter 412 for a loop offeeding fiber 402 to be contained within optical fiber tray 300. In someembodiments, minimum coil diameter 412 is chosen to be at least aminimum bend radius of feeding fiber 402. In some embodiments, minimumcoil diameter 412 is in the range of about 16 to 24 inches. In someembodiments, each of outer guide posts 410 are spaced apart from thenearest inner guide post 408 by a distance sufficient to contain aplurality of concentric loops of feeding fiber 402. In some embodiments,the height of and the distance between the inner guide posts 408 andouter guide posts 410 allow for 75 meters of feeding fiber 402 to becoiled in optical fiber tray 300. While shown as including two pairs ofinner guide posts 408 and outer guide posts 410, in some embodimentsonly one pair or three or more pairs may be used. In some embodiments,only inner guide posts 408 are used. Also, while the pairs of inner andouter posts are shown as positioned at 12 and 6 o'clock, in someembodiments they are at different relative positions, for example at 3and 9 o'clock. In some embodiments, a straight line from the inlet offeeding fiber 402 into optical fiber tray 300 to side fiber opening 404bifurcates the distance between one inner and outer guide post pair(depicted in FIG. 4 as line 424 bifurcating the distance between theguide post pair at the 12 o'clock position).

Ties 414 may be included in optical fiber tray 300 to fasten together aplurality of loops of feeding fiber 402. Ties 414 may represent reusablezip ties. In some embodiments, ties 414 may represent hook and loopties. While shown as including 3 Ties 414, any number of ties may beused. Also, while Ties 414 are shown as positioned at 1, 5 and 9o'clock, in some embodiments they are at different relative positions,for example at 3, 7 and 11 o'clock.

Liquid supply port 416 and liquid return port 418 may be included on thesame side of optical fiber tray 300 as, and may be within a few inchesof, side fiber opening 404. When laser system 100 is operating, highamounts of heat may be generated at the end of feeding fiber 402. Assuch, liquid supply port 416 may interface with external conduit tosupply liquid to (and liquid return port 418 may interface with externalconduit to return liquid from) a liquid thermal solution, such as acoldplate, to dissipate heat from the end of feeding fiber 402 through aliquid-cooling circuit. Optical fiber tray 300 may include liquid supplyconduit 420 and liquid return conduit 422 to extend the liquid-coolingcircuit to and from rack 200.

FIG. 5 is a drawing of a bottom of an example optical fiber tray, inaccordance with some embodiments. As shown, the bottom of fiber tray 300may include bottom fiber opening 500, electrical interface 504, liquidsupply port 506, liquid return port 508, drain port 510, and fastenerholes 512. In some embodiments, FIG. 5 also represents a bottom of anexternal module (minus feeding fiber 402, liquid supply port 416, andliquid return port 418).

Bottom fiber opening 500 may accept a feeding (or intermediary) fiberexiting from a top of laser system rack 200. Bottom fiber opening 500may be rectangular in shape with longer sides oriented in parallel withlonger sides of optical fiber tray 300. Bottom fiber opening 500 mayinclude housing that provides a fiber inlet to accept a fiber in asubstantially vertical orientation and bend it to a substantiallyhorizontal orientation.

Electrical interface 504 may be part of an electrical circuit to providepower from power distribution module 102 in rack 200 to elements ofoptical fiber tray 300 by interfacing with electrical contacts on racktop panel 204. While shown as being round, electrical interface 504 maybe rectangular or another shape. Electrical interface 504 may bepositioned equidistant from the longer sides of optical fiber tray 300.

Liquid supply port 506 and liquid return port 508 may be coupled withliquid supply conduit 420 and liquid return conduit 422, respectively,and may interface with corresponding ports in rack top panel 204. Liquidsupply port 506 and liquid return port 508 may be oriented in parallelwith, and within one diameter distance from, a longer side of opticalfiber tray 300.

Drain port 510 may allow any liquid that may leak from theliquid-cooling circuit within optical fiber tray 300 to drain down intoa corresponding opening in rack 200. Drain port 510 may be positionedalong the same side of optical fiber tray 300 as liquid supply port 506and liquid return port 508.

Fastener holes 512 may allow optical fiber tray 300 to be bolted tocorresponding fastener holes on rack top panel 204. Fastener holes 512may be present in each corner of optical fiber tray 300 as well alongmidway of the longer sides of optical fiber tray 300.

FIG. 6 is a drawing of a top of an example laser rack, in accordancewith some embodiments. As shown, rack top panel 204 may include fiberopening 600, electrical interface 604, liquid supply 606, liquid return608, drain 610, and fastener holes 612. In some embodiments, FIG. 6 alsorepresents a top of an external module (minus the wheels).

Fiber opening 600 may allow a fiber to exit rack 200 and transitionthrough bottom fiber opening 500. Fiber opening 600 may be rectangularin shape with its longer sides representing the approximate distancefrom fiber opening 600 to a side of rack 200 orthogonal to the longersides.

Electrical interface 604 may be oriented and configured to electricallycouple with electrical interface 504 when optical fiber tray 300 isplaced on rack 200. Electrical interface 604 include one or more pairsof power and ground connections.

Liquid supply 606 and liquid return 608 may interface with liquid supplyport 506 and liquid return port 508, respectively, to exchange waterbetween rack 200 and optical fiber tray 300 as part of a liquid-coolingcircuit. Drain 610 may interface with drain port 510 when optical fibertray 300 is installed on rack 200 to collect any liquid that leaks inoptical fiber tray 300.

Fastener holes 612 may form a bolt pattern that aligns with the boltpattern in the bottom of optical fiber tray 300 so that optical fibertray 300 can be securely mounted to rack 200 with screws. Fastener holes612 may be positioned in imaginary lines parallel to shorter sides ofrack 200, and 3 fastener holes 612 may be present along such a midwayline.

FIG. 7 is a diagram of an example laser system with an optical fibertray, in accordance with some embodiments. As shown, rack 200 mayinclude fiber opening 600, fiber housing 712, electrical interface 604,power distribution module 102, drain 610, liquid receptacle 708, andleak detector 710, while optical fiber tray 300 may include removabletop 702, bottom fiber opening 500, inner coil guides 408, outer coilguides 410, ties 414, split bushing 406, electrical interface 504, lighttower 706, pitched surface 704 and drain port 510.

Optical fiber tray 300 may include removable top 702 to allow access tothe interior of the enclosure. Removable top 702 may be hinged orunhinged. In some embodiments, removable top 702 rests on and can bebolted to standoffs (not shown) affixed to the interior bottom ofoptical fiber tray 300. In some embodiments, inner coil guides 408 andouter coil guides 410 extend high enough to support removable top 702and also function as standoffs.

Pitched surface 704 may be included in optical fiber tray 300 to directany liquid that may leak (for example from liquid supply conduit 420 orliquid return conduit 422) toward drain port 510. Pitched surface 704may extend 360 degrees around drain port 510 similar to a bathtub. Pitchsurface 704 may have a constant or variable pitch toward drain port 510.When optical fiber tray 300 is installed on rack 200, drain port 510would interface with drain 610 to transfer any liquid present throughdrain conduit to liquid receptacle 708 at or near the bottom of rack200. As liquid accumulates in liquid receptacle 708, it may be sensed byleak detector 710. Leak detector 710 may electrically and/orcommunicatively coupled with power distribution module 102 to respond toa detected leak. In some embodiments, a detected leak could cause powerdistribution module 102 to turn off power to laser modules in rack 200.In some embodiments, a detected leak could cause a warning light to bedisplayed on light tower 706.

Light tower 706 may be present on top of optical fiber tray 300 tocommunicate status information about laser system 100. Light tower 706may include any number and color of lights, perhaps LED lights. In someembodiments, light tower 706 receives DC voltage to operate from powerdistribution module 102 through electrical couplings with electricalinterfaces 504 and 604.

Fiber housing 712 may protrude from the top of rack 200 to guide exitfiber 108 into optical fiber tray 300. Fiber housing 712 may include across-support to allow exit fiber 108 to gradually bend fromsubstantially vertical to substantially horizontal. In some embodiments,fiber housing 712 is instead recessed within optical fiber tray 300.

FIG. 8 is a diagram of an example laser system with an external module,in accordance with some embodiments. As shown, laser system 100 mayinclude external module 800 which may include coupler 802, bottomopening 804, exit fiber 108, top opening 806, feeding fiber 402,fastener holes 810, electrical interfaces 812, drain openings 814, topliquid connections 816 and bottom liquid connections 818. While shown asincluding one external module 800, laser system 100 may include two ormore external modules 800 of similar or varying complexity. Externalmodules 800 can be inserted in between the rack 200 and optical fibertray 300 which do various things to the beam characteristics, withoptical fiber tray 300 being added to laser system 100 at the end of theoptical path. A common interface, as described in reference to FIG. 5and FIG. 6, at the top of rack 200 mates with either optical fiber tray300, or any other external module 800. The top of external modules 800would have the same interface as rack top panel 204, and optical fibertray 300 mated to the top of them. This approach enables a “plug andplay” implementation where an unlimited number of modules that canmodify the optical properties of the laser and be placed in the opticalpath. At the end of the path optical fiber tray 300 manages feedingfiber 402 for customer use.

Coupler 802 may be included in external module 800 to couple exit fiber108 received from rack 200 through bottom opening 804 with feeding fiber402 passed to optical fiber tray 300 through top opening 806. Coupler802 may represent any one or more optical couplers, such as including,but not limited to, a variable beam properties product (vBPP), afiber-fiber coupler (FFC), or a fiber-fiber switch (FFS). In someembodiments, coupler 802 may be included within optical fiber tray 300.Coupler may be designed to modify properties of light driven throughfeeding fiber 402 or may pass light through unaltered.

Fastener holes 810 in external module 800 may match with the boltpatterns of fastener holes 512 of optical fiber tray 300 and fastenerholes 612 of rack 200, such that external module 800 can be securelymounted in laser system 100. The enclosure of external module 800 mayinclude a removable top to allow access to the interior of theenclosure, for example to couple fibers and install screws.

External module 800 may also include a bathtub-like pitch bottom todirect liquid to the bottom of drain openings 814, which interface withand couple drain port 510 with drain 610. Top liquid connections 816 mayinterface with and couple liquid supply port 506 and liquid return port508 through conduit to liquid supply 606 and liquid return 608,respectively, which may interface and couple with bottom liquidconnections 818. While shown as bridging the liquid-cooling circuitbetween rack 200 and optical fiber tray 300, in some embodiments,external module 800 may include branches off of the liquid-coolingcircuit, for example directed to a coldplate at coupler 802.

A flowchart of an example method of assembling a laser system, inaccordance with some embodiments, is shown in FIG. 9. The method beginswith installing (902) external module 800, if it is to be used, on rack200, in some embodiments. A top of external module 800 may be removed toinstall screws or bolts through fastener holes 810 into fastener holes612.

The method continues with connecting (904) exit fiber 108, which may bepulled up through fiber opening 600, and feeding fiber 402 to coupler802, in some embodiments. After the fibers are connecting a top, whichmay have a bolt pattern matching that of fastener holes 612 of rack toppanel 204, may be replaced on external module 800. Additional externalmodules 800 may be installed in a similar manner.

Next, optical fiber tray 300 is installed (906) on external module 800(if present as in FIG. 8) or on rack 200 (if external module 800 is notincluded). Removable top 702 may be removed to access the interior ofoptical fiber rack 300. Screws or bolts tightened through fastener holes512 to secure optical fiber rack 300 in place. Feeding fiber 402 may bepulled up through bottom fiber opening 500.

The method concludes with coiling (908) feeding fiber 402 within opticalfiber tray 300 between inner coil guides 408 and outer coil guides 410,in some embodiments. The coils of feeding fiber 402 may be held togetherby one or more of ties 414. Removable top 702 may then be replaced andsecured.

FIG. 10 is a flowchart of an example method of readying a laser systemfor use, in accordance with some embodiments. The method begins withaccessing (1002) the interior of optical fiber tray 300 by removingremovable top 702, in some embodiments.

The method continues with uncoiling (1004) and moving feeding fiber 402out through side fiber opening 404, in some embodiments. In someembodiments, split bushing 406 would need to be removed from side fiberopening 404 to allow access for feeding fiber 402. A number of coils offeeding fiber 402 may be lifted up and over inner coil guides 408 andouter coil guides 410 until the needed length of feeding fiber 402 hasbeen moved out of optical fiber tray 300.

Next, split bushing 406 may be secured (1006) within side fiber opening404, in some embodiments. Split bushing 406 may include screw-on orsnap-on pieces to grip feeding fiber 402 and hinder movement of feedingfiber 402 into or out of side fiber opening 404.

The method concludes with connecting (1008) conduit to liquid supplyport 416 and liquid return port 418, in some embodiments. In someembodiments, main liquid supply and return conduits would need to beconnected to ports in rack 200 that interface with liquid supply port416 and liquid return port 418 in optical fiber tray 300.

While certain features set forth herein have been described withreference to various implementations, this description is not intendedto be construed in a limiting sense. Hence, various modifications of theimplementations described herein, as well as other implementations,which are apparent to persons skilled in the art to which the presentdisclosure pertains are deemed to lie within the spirit and scope of thepresent disclosure. It will be recognized that the invention is notlimited to the embodiments so described, but can be practiced withmodification and alteration without departing from the scope of theappended claims. The above embodiments may include the undertaking ofonly a subset of such features, undertaking a different order of suchfeatures, undertaking a different combination of such features, and/orundertaking additional features than those features explicitly listed.The scope of the invention should, therefore, be determined withreference to the appended claims, along with the full scope ofequivalents to which such claims are entitled.

What is claimed is:
 1. An optical fiber tray for a laser system rack,comprising: an enclosure coupled with the laser system rack; anelectrical interface in a surface of the enclosure to contact acorresponding interface in a surface of the laser system rack; a firstopening in the enclosure to accept a feeding fiber exiting from thelaser system rack; a second opening in the enclosure to allow passage ofthe feeding fiber out of the enclosure; and a user-accessible spacewithin the enclosure to contain a length of the feeding fiber extendingfrom the first opening to the second opening.
 2. The optical fiber trayof claim 1, further comprising coil guides in the enclosure, the coilguides comprising a pair of inner posts and a pair of outer posts, theinner posts spaced apart by at least twice a minimum bend radius of thefeeding fiber and each of the outer posts spaced apart from a nearestone of the inner posts by a distance sufficient to contain a pluralityof concentric loops of the feeding fiber.
 3. The optical fiber tray ofclaim 1, further comprising one or more reusable ties affixed within theinterior of the enclosure to fasten together a plurality of loops of thefeeding fiber.
 4. The optical fiber tray of claim 1, wherein the secondopening in the enclosure comprises a split bushing to grip the feedingfiber while the bushing is disposed within the side of the enclosure. 5.The optical fiber tray of claim 1, further comprising first liquidsupply and return ports in a bottom of the enclosure to interface withcorresponding second liquid supply and return ports in a top of thelaser system rack.
 6. The optical fiber tray of claim 5, furthercomprising liquid supply and return ports in a side of the enclosure tointerface with conduit external to the enclosure, a liquid supplyconduit extending between the first and second liquid supply ports, anda liquid return conduit extending between the first and second liquidreturn ports.
 7. The optical fiber tray of claim 6, wherein theenclosure further comprises a surface pitched toward a drain in thebottom of the enclosure, the drain to interface with drain conduit ofthe laser system rack.
 8. The optical fiber tray of claim 1, wherein theenclosure further comprises a light tower electrically coupled with theelectrical interface.
 9. The optical fiber tray of claim 1, furthercomprising a fiber coupler to couple the feeding fiber with a secondfiber.
 10. A laser system, comprising: a rack, comprising: a pluralityof laser modules mounted in the rack to drive light through an opticalfiber exiting the system; a power distribution module disposed withinthe rack to distribute input electricity to the laser modules; and a toppanel; and an optical fiber tray mounted on the top panel of the rack,the optical fiber tray comprising: an enclosure; an opening in a bottomof the enclosure to accept a feeding fiber exiting from the top panel ofthe rack; an opening in a side of the enclosure to convey the feedingfiber outwardly; and a removable top panel to allow access to aninterior of the enclosure.
 11. The laser system of claim 10, wherein thetop panel of the rack further comprises a protruding housing to presentthe feeding fiber to the optical fiber tray substantially horizontally.12. The laser system of claim 10, further comprising an electricalinterface in the top panel of the rack to electrically couple theoptical fiber tray with the power distribution module.
 13. The lasersystem of claim 10, further comprising liquid supply and return ports inthe top panel of the rack to exchange liquid with the optical fibertray.
 14. The laser system of claim 13, further comprising a drain inthe top panel of the rack coupled with a receptacle, and a leak detectorin the receptacle to detect the presence of liquid.
 15. A laser system,comprising: a rack, comprising: a plurality of laser modules mounted inthe rack to drive light through an optical fiber exiting the system; apower distribution module disposed within the rack to distribute inputelectricity to the laser modules; and a top panel; an external modulemounted on the top panel of the rack, the external module comprising: anenclosure; an opening in a bottom of the enclosure to accept a firstfiber exiting from the top panel of the rack; a coupler to couple thefirst fiber to a feeding fiber; and an opening in a top of the enclosureto pass the feeding fiber; and an optical fiber tray mounted on the toppanel of the external module, the optical fiber tray comprising: anenclosure; an opening in a bottom of the enclosure to accept the feedingfiber exiting from the top of the external module; an opening in a sideof the enclosure to convey the feeding fiber outwardly; and a removabletop panel to allow access to an interior of the enclosure.
 16. The lasersystem of claim 15, wherein the coupler further comprises a device tomodify properties of light driven through the feeding fiber.
 17. Thelaser system of claim 15, wherein the external module enclosure furthercomprises liquid supply, return and drain ports in the enclosure top andbottom to couple the rack with the optical fiber tray.
 18. The lasersystem of claim 15, wherein the external module enclosure furthercomprises electrical interfaces in the enclosure top and bottom toelectrically couple the rack with the optical fiber tray.
 19. The lasersystem of claim 15, wherein the external module enclosure furthercomprises a plurality of fastener holes forming a pattern in theenclosure top and bottom, the pattern matching fastener holes in the topof the rack.